The biogeographic regionalization of the Sierra Madre del Sur province is reviewed, considering recent proposals and applying the International Code of Area Nomenclature to name the 3 subprovinces and 5 districts recognized. The Western Sierra Madre del Sur subprovince, situated in the states of Jalisco, Colima and Michoacán, comprises the Jaliscan and Jaliscan-Manantlán districts. The Central Sierra Madre del Sur subprov. nov., situated in the state of Michoacán, comprises the Michoacán district. The Eastern Sierra Madre del Sur subprovince, situated in the states of Guerrero, Oaxaca and Puebla, comprises the Guerreran and Oaxacan Highlands districts. Diagnoses of these areas are provided and their endemic taxa are listed.

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Introduction

The Sierra Madre del Sur biogeographic province, situated in south-central Mexico mainly between the Balsas Basin and the Pacific Lowlands provinces, has been assigned to the Mexican transition zone ( Morrone, 2010, 2014 ). Several authors have recognized the Sierra Madre del Sur as a distinct biogeographic province, although its boundaries differ widely among different regionalizations (see Santiago-Alvarado, Montaño-Arias, & Espinosa, 2016 ). Some nested units that have been identified within this province ( Arriaga, Aguilar, Espinosa, & Jiménez, 1997 ; Escalante, Navarro, & Peterson, 1998 ; Ferrusquía-Villafranca, 1990; Smith, 1941 ) were treated preliminary by Morrone (2014) as the Guerrero, Central Valley, Isthmian, Nudo de Zempoaltépetl, Oaxacan Highland and Sierra de Miahuatlán districts. Santiago-Alvarado et al. (2016) recently reviewed the delimitation of the Sierra Madre del Sur biogeographic province and its regionalization. They considered that the boundaries of the Sierra Madre del Sur ecoregion ( Inegi-Conabio-INE, 2008 ) were more appropriate, because they are based on climatic, geological and biological criteria, unifying different schemes into a single system, as suggested by Challenger and Soberón (2008) . This new circumscription incorporates, in addition to the province as previously recognized by most authors (e.g., Arriaga et al., 1997; Goldman & Moore, 1945; Morrone, 2005, 2010, 2014 ), 2 disjunct areas in the states of Jalisco and Michoacán. Additionally, Santiago-Alvarado et al. (2016) recognized 2 subprovinces: Western Sierra Madre del Sur (with the Jaliscan-Tuito, Jaliscan-Manantlán and Michoacán districts) and Eastern Sierra Madre del Sur (with the Guerreran and Oaxacan districts).

The objectives herein are to review the biogeographic regionalization of the Sierra Madre del Sur province, especially considering the schemes proposed by Morrone (2014) and Santiago-Alvarado et al. (2016) ; to provide the valid names of the areas recognized, applying the International Code of Area Nomenclature (ICAN; Ebach, Morrone, Parenti, & Viloria, 2008 ); and to list the diagnostic taxa of the different areas recognized.

Diagnosis. South-central Mexico, in the states of Jalisco, Colima, Michoacán, Guerrero, Oaxaca and parts of Puebla. It spans for ca. 1,100 km, has an average width of 120 km and an altitude above 1,000 m (Santiago-Alvarado et al., 2016 ). It is situated south of the Balsas Basin biogeographic province and north of the Pacific Lowlands province. As circumscribed by Santiago-Alvarado et al. (2016) , it is not continuous but it splits into 3 disjunct areas, treated herein as subprovinces.

Subprovinces. Three subprovinces are recognized, corresponding to the 3 disjunct areas of the province ( Fig. 1 ): Western Sierra Madre del Sur, Central Sierra Madre del Sur and Eastern Sierra Madre del Sur. Santiago-Alvarado et al. (2016) considered the 2 former as a single subprovince, but based on the evidence available I consider it better to split it into 2 subprovinces.

Megastigma chiangii (Rutaceae) a new species of the Sierra Madre del Sur of the Guerrero State, Mexico

Brittonia

67

2015

56-8

Köhler et al., 2014

G. Köhler

R. Gómez-Trejo

C.B.P. Petersen

F.R. Méndez-de la Cruz

A revision of the Mexican Anolis (Reptilia, Squamata, Dactyloidae) from the Pacific versant west of the Isthmus de Tehuantepec in the states of Oaxaca Guerrero, and Puebla, with the description of six new species